The process for creating motion pictures is continually evolving. One of the more recent developments involves what is commonly referred to as a digital intermediate process (“DI process”). In general, the DI process involves the temporary conversion of film to a digital format for the production and editing process. When this process is complete, the motion picture is recorded from the digital format back to film again. The process for converting the original film to digital format can vary. However, current technology will typically scan film at a resolution of 2 K (2048×1556) and 10 bits per color channel. Although this level of resolution is currently deemed acceptable for release, it does not capture all of the information on the film negative. With the improvement in technology, the scanning resolution and color bit depth is expected to improve.
With current technology and economic considerations, the DI process does not take advantage of the full image quality of the original camera negative (OCN) or other image acquisition medium. Therefore, archiving the post production film created after the DI process is complete does not preserve the full image quality that is available. In contrast, archiving the OCN or other image acquisition medium can preserve the original image quality. However, archiving the original OCN material does not preserve the artistic intent as embodied in the production process and release. One solution might be to archive both the post production film created after DI and the OCN. However, archiving both sets of materials is expensive
Film material is best archived by making three monochrome separations that capture the content of the Yellow, Cyan and Magenta (YCM) layers of the OCN. Such archives are believed to have a viable life of around 500 years. Separations are usually made from “timed” intermediates, with some image quality loss. Alternatively, the separations can be made using the timing information to create separations from the OCN, in which case artistic intent is preserved. There are advantages to creating separations from the OCN using “nominal” exposure values and no printing-light correction so as to capture the full dynamic range of the OCN. This approach ensures that no image information is lost. However, the creation of separations using this technique does not convey any information about how the negative was timed and printed. The result is a loss of information regarding color correction and so on. Accordingly, this information regarding the original release is not preserved. Consequently, the artistic intent of the director may be lost.
One known technique for providing a color-correction reference for the full length timed print of a motion picture involves use of a “key frame reel” or “trial print”. The key frame reel normally contains three frames (first, middle, last) for each scene, to provide a color correction reference for making the full-length timed print. The longevity of the InterPostive (IP) obtained using this process is estimated at about 150 years. However, the IP is known to degrade continuously. Consequently, the key frame reel does not provide a reference for preserving artistic intent that has the longevity of OCN monochrome separations.